I'm not sure really, which is the best forum for this question - so I've filed it under "ideas".

I'm looking at replacing my PC, this Summer. Unfashionably perhaps, but for practical purposes it will be based around some sort of Intel running XP. The issue I'm raising here is that amongst the possible 'bells and whistles' widely available is the possibility of adding a second monitor.

I can see a number of possible uses for a second monitor (e.g. develop on one, view on the other, etc.) but the question is; Just how useful is a second monitor? Does anyone here use one regularly? What's your experience - Brilliant, nice or a waste of deskspace? How practical are they in practice? I'd really like to know.

I have a 2 mon setup at work, it really is very useful. Once you get used to it though, it's very difficult to go back!

Space/$ restrictions mean I can't have the same setup at home and since I'm used to having so much desktop space at work I find it very frustrating working on my home computer now. doh!

It's great being able to devote a whole monitor to google, or your API docs; with your IDE up in the adjacent monitor. Having to switch windows back/forth disrupts your focus. Especially for dev work where I like to have an IDE, a browser, a console, email etc windows open simultaneously. The problem isn't so bad if you are using a lightweight editor for coding I suppose. There are workarounds.

I used to have to set my screen resolution really high to increase my desktop real estate. It would give me headaches though. I also find that XP is very "chunky", although you can probably change the window styles.

If you can put up with the extra space required on your desk, or you plan on getting 2 flat panels, do it, but be warned; It's a luxury you will soon not be able to do without!

I have a big monitor and a small monitor, with the second monitor set off quite a bit, which is mostly devoted to reading email. Mostly, I'd get a new message and become distracted and lose my concentration (even with virtual desktops), so a second monitor lets me multitask this better, and I use separate virtual desktops for entirely separate tasks. I find that I don't do quick visual switches though -- like documentation in one screen and editor in another. I think you'd want two similar monitors, physically close to each other and at the same distance if you want to be able to switch between them quickly, so that you don't refocus your eyes or temporarily lose your mouse cursor when moving between the two of them. But I still like two monitors even without that.

I have a 23 inch digital Apple Cinema Display attached to my Mac Dual G4, which is like having two monitors, I can view two full-sized documents at 100 percent side-by-side with plenty of room to spare. I have yet to find a Wintell machine that can match the overall performance or compile speed of this setup (can't wait to get my hands on a G5). The sheer size of the Cinema Display, its non-reflective properties, along with its clarity and color fidelity is well beyond anything else on the market. I use CodeTek's Virtual Desktop configured with 9 desktops to switch between, which is like having 18 monitors! From a developer's point of view, this is one of the most efficient and productive setups you could imagine.

The Cinema Display takes up very little desk-space and throws virtually no heat. I can attach another monitor or flat panel to my Mac without any special hardware or software and arrange it so that I have a continuous desktop. Sitting in front two honking big, power hungry CRTs and wrestling with Winbloze XP is not a very appealing thought compared to development on a Cinema display with OS X! Check out my "News and Ideas" post on OS X:

I agree with Greg - 2 monitors is VERY useful. I'm scrounging around for parts to have a 3rd right now! Here's my reasoning:

Assuming WindowsOS (adjust as needed for Linux or other), on one monitor with many programs running you end up alt-tabbing a lot or looking at the start bar with many buttons that don't have near enough information to figure out which program is which, especially if a lot of them are multiple copies of say, Windows Explorer, a browser, or maybe a code editor (non-MDI, that is, if that's your style). Or you have all of our open windows tiled in some sort of layout where none of them is very big so that you can always see the one you want to click on to switch to.

With two monitors (in my case, both 19" running at 1600x1200) I have room to make the windows larger and spread them out. I use one as my primary for things like IDE, source control, database browser, and e-mail, and the other for Windows Explorer, browser windows, and other miscellaneous stuff. I do a lot of web development with servlet/JSP so one thing I am able to do is put two 800x600 windows (the resolution we develop for) side-by-side on the non-primary window with a log file window behind them and still be able to have my IDE nearly full-screen on the primary. The ability to be looking at the output of a program, it's the log of it's execution, and a large real estate of the code that produced it is invaluable. I can honestly say that I'm many times more productive than before I had two monitors.

But, I now feel like three would be pretty close to ideal. This is for two reasons: One, so I can move the real-time log file and API documentation viewer to the third monitor, but also so I can run it in a lower resolution like 1280x124 or 1152x864 so that I can move whatever window I need over to the third screen and have it instantly "zoom in". I need this because I frequently have visitors who come look over my shoulder to either see a demo, look at a piece of code, or view a particularly interesting webpage I've found. And 90% of the time my visitors can't read my 1600x1200 text, especially since they are always further from the screen.

I know of non-coders who have gone overboard and use 4-8 monitors, each one full-screen on some valuable piece of electronic information. This is especially useful for people in financial industries that need real-time data from several sources, lists of rates, etc. These people claim magnitudes of order increases in ability to move quickly and often directly attribute increased pay/profit to this efficiency.

I say absolutely without a doubt get another monitor. Try to make it about the same size/quality/resolution so you can stretch your desktop without having 'gaps' when moving windows from one screen to another, which can be disconcerting.

For me, the most compelling reason for a 2-monitor setup would be to read programming books in pdf format. I have a lot of these, and it's painful to copy code from the book. I have to keep my VIM editor half the monitor's size, and alt-tab every few lines. I know how much a help would it be to move the pdf book to other monitor and try out the code in another. I intend to buy the second one real soon.

I would say that two monitors is just a waste of desk space and money, though I've never used such a setup myself. However using a desktop switcher (like the free <a href="http://hem.fyristorg.com/jspage/">JSPager</a> for windows) helps a lot. I always use a 3x3 setup on both linux and windows and I found that I can't really work without this feature anymore. That's why I think that the 2-monitor setup is quite useless, because it simply doesn't give you enough screen estate most of the time.

I find it incredibly helpful two have two. In Win XP, i use the extra space so that the APP i run/debug is on one monitor and the ide is on the other. with this setup, I can set a break point without worrying about extra repaint messages getting in the way.

choose your video card(s) wisely. if you are doing two with 1 PCI and 1 AGP avoid mixing brands as this is usually a bugger to configure. why two boards? XP/win2k is better at being aware of maximized windows taking up a single monitor instead of stretching across the whole "canvas" by default. it also seems smarter about preventing dialog straddle ie popping up across two monitors so that its half on one monitor and half on the other (ARRRGH!) NVIDIA's desktop manager is getting better but its not perfect. I gave up on the ATI offering in about 24 hours and never looked back.

If you go with a single video board get dual DVI outs (not the inverse) since once day you will upgrade to dual LCD. going DVI to analog i didnt notice a loss, but analog to digital for lcd will grate you when you count how much you are spending for dual LCD's.

If you arent going LCD also take a look a the wattage becuase you are going to have more heat/engery consumption to contend wtih. Remember that amps * voltage will give you an approximation of wattage. my dual setup at home , used about 6 hrs a day, is the second biggest draw of hydro behind my freezer because they each draw 3.0 amps. Something I didnt pay attention to when i intially bought them.

one last thing, also make sure your desk is sturdy, my buddy didnt check this out and when he foisted two 19" on his desk it cracked!

Having used both dual displays, virtual desktops, and dual displays with virtual desktops I would have to say that a good virtual desktop system will give you most of what you need.

This avoids the cost and desk space of a second monitor.

The fact is that you can only look at one thing at a time (although periphery vision can be useful in some computing contexts). If you have a virtual desktop for each "monitor worth" of applications, you can essentially get the same effect, with the advantage that you don't have to turn your head to get access to it.

Where dual displays together with virtual desktops can become useful is where you have more then 3 or 4 different screens worth of stuff that you are working on at a time. In this case, you can group related screenfuls of applications together across the two (or more) screens as giant virtual desktops.

The other thing is that virtual desktops on windows can be a bit flaky because they are not really supported by the window manager, with Linux it tends to work pretty smoothly.

I'm using an IBM Thinkpad T30 laptop (14.1" 1400x1050) and a Viewsonic 18" 1280x1024; fortunately the T30 allows you to use the internal and external display together. I think it's really, really nice to have two monitors, especially when debugging (and it's a lifesaver when you are running two debuggers simultaneously!). It's also nice for Photoshop work, so you have somewhere to put all those palettes, as designers on Mac have done for many many years.

That said, if it were my money and I were choosing between one display or two, I think I might keep my money. It's a really nice luxury, but a luxury nonetheless.

(On the other hand, an older and better-heeled coworker of mine paid for dual 18" flatscreens at both work and home...)

Two monitors are fantastic, and two monitors together with a KVM switch are true bliss. I have the following setup at the office:

Two 18" flatpanels: the left monitor is the 2nd monitor on my Windows machine. The other monitor is my "main" monitor right in front of me and is connected to a KVM which is connected to the 1st VGA out of my windows machine and whatever else is currently relevant (Linux, XP test machine, etc). The mouse/keyboard is connected to the KVM. This setup allows me to:

- Use full screen space on my Windows machine (think big spreadsheets) by switching the main monitor to the windows machine.

- Pull up reference docs/emails/etc on the windows, pop them on the left monitor, switch to another computer and still refer to these docs.

- Work on a secondary machine while still keeping an eye on my mail on the windows machine.

I say two monitors are worth it, no question. It's one of these choices which is hard to justify beforehand but you will find so many uses for the setup once you have it you will not want to go back.

Two monitors are indespensible for development where the primary (24") monitor is used for the IDE and the secondary monitor (17") is used for reference (browser/pdf/etc.) and as a KVM monitor for various servers. As mentioned above, it would be very hard to go back to a single monitor config.